The disclosure relates to an apparatus and to a method for providing safety measures during gas release from a vehicle battery, in particular from a damaged lithium-ion rechargeable battery for hybrid or electric vehicles. The disclosure further relates to an installation space for a vehicle battery.
In electric and hybrid electric motor vehicles, galvanic cells are used as energy stores. In this context, lithium-ion rechargeable batteries (also called lithium-ion batteries) are used in particular as the vehicle battery providing the energy required for the drive. These, and also in principle other galvanic cells, have a number of problems. Disturbances, such as the occurrence of high electric currents, overcharging of the vehicle battery during the charging operation or high external temperatures, can thus lead to what is termed thermal runaway and as a consequence thereof to overheating of the battery cells of the vehicle battery. Flammable gas, for example ethane, methane and other hydrocarbon gases, forms in the affected battery cells, this gas formation bringing about a pressure increase inside the battery cells.
Safety vents or air vents arranged at the top end of the housing of a battery cell are known in the prior art as apparatuses for providing safety measures during gas release from a vehicle battery. These safety vents are formed in such a manner that they open with an increasing pressure inside the battery cell and therefore make it possible for the gas mixture to be released (also referred to as release of gas hereinbelow) from the battery cell. What are termed degassing channels are known in the prior art as further apparatuses for providing safety measures during gas release from a vehicle battery. When a plurality of battery cells are connected together to form a battery module, a degassing channel of this type is arranged above the air vents of the battery cells and is connected in this way to the individual battery cells. Here, the degassing channel carries released gases away from the vehicle to the atmosphere via a discharge opening, as a result of which the vehicle occupants in particular are protected from the released gases.
However, the use of such degassing channels leads to the structural disadvantage that electronic components, particularly those required for the battery management, cannot be arranged on the battery modules. The arrangement of the electronic components on the battery modules has proved to be structurally expedient, however. A further disadvantage of the use of such degassing channels is that the throughput of released gas is often unsatisfactory. Thus, gas released from damaged battery cells can often not be dissipated quickly enough via the degassing channel, as a result of which the internal pressure in the degassing channel rises rapidly. As a result of the increased internal pressure, the air vents of previously undamaged battery cells too are opened or broken open, as a result of which the released gas also penetrates into these, previously undamaged battery cells, and the latter can therefore likewise be damaged. In particular, the rising internal pressure in the battery cells owing to the released gas can lead to a cascade of explosions, which can not only destroy the vehicle battery, but also represent a safety risk for the vehicle and its occupants.
Against this background, the disclosure is based on the object of improving the dissipation of gas released from damaged battery cells and of at least partially neutralizing released gases, while avoiding the aforementioned disadvantages.